Unit 2: Evolution of Cloud Microservices - Practice Quiz

1 What is a monolithic application architecture?

2 How do components in a distributed application commonly communicate?

3 What is a common limitation of monolithic architecture?

4 What is a potential benefit of distributed architecture?

5 What does a microservice usually represent?

6 Which characteristic is commonly associated with a microservice?

7 How do microservices commonly exchange information?

8 Which practice supports loose coupling between microservices?

9 What is microservices architecture?

10 Which deployment approach is typical in microservices architecture?

11 What does fault isolation mean in a microservices system?

12 Which organizational approach commonly supports microservices?

13 In domain-driven design, what does the term domain refer to?

14 What is a bounded context in domain-driven design?

15 What is the purpose of a ubiquitous language in DDD?

16 Who should help develop the domain model in DDD?

17 What does a service boundary define?

18 Which quality indicates a well-defined service boundary?

19 What is the main role of an API gateway?

20 Which task is commonly performed by an API gateway?

21 A team modifies the payment logic inside a tightly coupled monolithic application. What is the most likely deployment consequence?

22 An order service calls an inventory service that is temporarily unavailable. Which approach best addresses this distributed-system failure?

23 Two services must always be released together because they directly depend on each other's internal classes. Which microservice property is most clearly being violated?

24 Why is assigning each microservice ownership of its own data generally preferred?

25 A product page synchronously calls pricing, inventory, reviews, and recommendation services. One slow dependency frequently delays the whole page. Which improvement is most appropriate?

26 An order service publishes an OrderCreated event, and the inventory service processes it asynchronously. Which consequence should the design handle?

27 In a retail platform, the term Product means an item for sale in Catalog but a stored unit in Inventory. How should DDD represent these meanings?

28 Developers and business experts use different names for the same shipping concepts, causing recurring misunderstandings. Which DDD practice best addresses this problem?

29 A purchase order must ensure that its total always equals the sum of its line items whenever it is updated. Which DDD concept should define this consistency boundary?

30 A new billing service must integrate with a legacy system whose data model uses incompatible terminology. Which DDD pattern best protects the new domain model?

31 Customer profile and loyalty rules change for different business reasons and are managed by different teams. What is the best boundary decision?

32 Several services directly update the same database tables. What is the main architectural risk?

33 A single CommerceService handles catalog, pricing, orders, payments, and shipping, and unrelated changes frequently conflict. Which criterion is most useful when splitting it?

34 After decomposition, retrieving one customer page requires dozens of synchronous service calls for tiny pieces of data. What does this most likely indicate?

35 Mobile clients currently call eight internal services and must know each service location. What is the primary benefit of introducing an API gateway?

36 A team wants consistent authentication, request routing, and rate limiting for public APIs. Where should these cross-cutting concerns primarily be implemented?

37 A gateway contains pricing rules, discount calculations, and order approval logic. What is the best architectural improvement?

38 Web and mobile clients require substantially different response shapes for the same platform capabilities. Which gateway-related approach is most suitable?

39 A payment, order, and inventory workflow spans separate services without a shared transaction manager. Which pattern is most appropriate for coordinating the workflow?

40 A user request passes through a gateway and four services, but logs cannot be connected across components. Which addition would most improve diagnosis?

41 A tightly coupled monolith has modules that share tables, internal classes, and transaction boundaries. The organization wants to migrate incrementally to microservices while minimizing distributed-system risk. What should be done first?

42 A request succeeds only if four independently failing synchronous services are available. Each service has availability , and network failure is ignored. What is the approximate end-to-end availability?

43 Two independently deployed services directly update different columns of the same database table. Schema changes require coordinated releases, although each service has a separate code repository. Which microservice property is most directly violated?

44 An Order service must save an order and publish an OrderCreated event. A crash between the database commit and broker publication currently causes lost events. Which design best closes this failure window without a distributed transaction?

45 In Sales, Customer means a prospect or buyer with pricing terms. In Support, Customer means a party associated with cases and service-level agreements. Which DDD treatment is most appropriate?

46 A business rule states that the total allocation across all lines of a Budget must never exceed its approved amount at commit time. Which aggregate design most strongly preserves this invariant?

47 Inventory and Pricing are maintained by different teams and change for different business reasons. Checkout synchronously invokes both services many times while constructing one cart response, causing latency and release coordination. Which redesign best addresses the boundary problem without merging unrelated domains?

48 A proposed service contains operations that always change together, share one strict invariant, and are owned by the same team. Splitting those operations would require a saga for nearly every command. What is the strongest architectural conclusion?

49 A gateway authenticates users, applies quotas, routes requests, and also decides whether an order qualifies for a domain-specific refund. What is the best correction?

50 A gateway times out after two seconds and retries POST /payments once. The first attempt may complete after the timeout, creating duplicate charges. Which control provides the strongest end-to-end protection?

51 A checkout saga reserves inventory, authorizes payment, and requests shipment. Shipment creation fails after payment authorization. Payment authorization can be voided, but the inventory reservation may already have expired. What should the saga do?

52 An event consumer updates its database and then crashes before acknowledging the message. The broker redelivers the event. Which assumption should the consumer design make?

53 A legacy billing model is inconsistent with a new Subscription bounded context. Reusing legacy billing objects directly would force legacy terminology and rules into the new model. Which DDD pattern best isolates the new context?

54 A downstream context has no influence over an upstream vendor model and chooses to adopt that model exactly rather than maintain translation logic. Which DDD context-map relationship does this describe?

55 A team proposes one microservice per database entity: Customer, Address, PhoneNumber, and EmailPreference. Most use cases require coordinated calls to all four, and they are released by one team. Which signal most strongly indicates poor boundaries?

56 Service A needs a small subset of Service B's data to validate commands even when B is temporarily unavailable. Slightly stale validation data is acceptable, but A must not write B's records. Which design best preserves ownership and resilience?

57 A single gateway instance handles all external traffic and stores rate-limit counters and sessions only in local memory. Which change most directly removes both the availability bottleneck and state-related scaling constraint?

58 After validating a user token, a gateway forwards an unsigned X-User-Role header to internal services. Some services are also reachable through an internal network path that bypasses the gateway. What is the primary security flaw?

59 During a strangler migration, /accounts requests are routed to a new service, but both the monolith and the service can update account balances. Reconciliation repeatedly finds divergent balances. What is the most important corrective action?

60 A distributed request crosses six services using asynchronous messaging and background workers. Logs contain timestamps but cannot reliably connect work performed after queue delivery to the original request. Which observability mechanism best addresses this?